Substrates with electronically active components distributed over the extent of the substrate may be used in a variety of electronic systems, for example, in flat-panel display devices such as flat-panel liquid crystal or organic light emitting diode (OLED) displays, in imaging sensors, and in flat-panel solar cells. The electronically active components are typically either assembled on the substrate, for example using individually packaged surface-mount integrated-circuit devices and pick-and-place tools, or by sputtering or spin coating a layer of semiconductor material on the substrate and then photolithographically processing the semiconductor material to form thin-film circuits on the substrate. Individually packaged integrated-circuit devices typically have smaller transistors with higher performance than thin-film circuits but the packages are larger than can be desired for highly integrated systems.
Methods for transferring active components from one substrate to another are described in U.S. Pat. No. 7,943,491. In examples of these approaches, small integrated circuits are formed on a native semiconductor source wafer. The small unpackaged integrated circuits, or chiplets, are released from the native source wafer by etching a layer formed beneath the circuits. A PDMS stamp is pressed against the native source wafer and the process side of the chiplets is adhered to individual stamp posts. The chiplets are pressed against a destination substrate or backplane with the stamp and adhered to the destination substrate. In other examples, U.S. Pat. No. 8,722,458 entitled Optical Systems Fabricated by Printing-Based Assembly teaches transferring light-emitting, light-sensing, or light-collecting semiconductor elements from a wafer substrate to a destination substrate or backplane.
In order to populate a large destination substrate with components from a native source wafer, the stamp repeatedly picks up components from different locations on the native source wafer with stamp posts and prints the components to different locations on the destination substrate. The arrangement of components on the destination substrate is at least partly defined by the arrangement of the components on the native source wafer and the arrangement of posts on the stamp. The location of the stamp with respect to the native source wafer and the destination substrate is controlled by an opto-electro-mechanical control system.